The pintle injector is a type of propellant injector for a bipropellant rocket engine. Like any other injector, its purpose is to ensure appropriate flow rate and intermixing of the propellants as they are forcibly injected under high pressure into the combustion chamber, so that an efficient and controlled combustion process can happen.[1]
A pintle-based rocket engine can have a greater throttling range than one based on regular injectors, and will very rarely present acoustic combustion instabilities, because a pintle injector tends to create a self-stabilizing flow pattern.[2][3] Therefore, pintle-based engines are specially suitable for applications that require deep, fast, and safe throttling, such as landers.[4]
Pintle injectors began as early laboratory experimental apparatuses, used by Caltech's Jet Propulsion Laboratory in the mid-1950s, to study the mixing and combustion reaction times of hypergolic liquid propellants. The pintle injector was reduced to practice and developed by Space Technology Laboratories (STL), then a division of Ramo-Wooldridge Corp., later TRW, starting in 1960.[2]
There have been pintle-based engines built ranging from a few newtons of thrust up to several millions, and the pintle design has been tested with all the common and many exotic propellant combinations, including gelled propellants.[2] Pintle-based engines were first used on a crewed spacecraft during the Apollo Program in the Lunar Excursion Module's Descent Propulsion System,[4][2][5] however, it was not until October 1972 that the design was made public.[2][3] and U.S. patent 3,699,772 was granted to its inventor Gerard W. Elverum Jr.[6]
^Krzycki, Leroy J. (1967). How to Design, Build and Test Small Liquid-Fuel Rocket Engines. United States of America: ROCKETLAB. pp. 23.
^ abcde
Dressler, Gordon A.; Bauer, J. Martin (2000). TRW Pintle Engine Heritage and Performance Characteristics(PDF). 36th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Joint Propulsion Conferences. AIAA. doi:10.2514/6.2000-3871. AIAA-2000-3871. Archived (PDF) from the original on 2017-08-10. Retrieved 14 May 2017.
^ ab
William R. Hammock, Jr.; Eldon C. Currie; Arlie E. Fisher (March 1973). "Apollo Experience Report - Descent Propulsion System" (PDF). NASA Technical Reports Server. Archived (PDF) from the original on 2017-05-04.
^Cite error: The named reference :4 was invoked but never defined (see the help page).
The pintleinjector is a type of propellant injector for a bipropellant rocket engine. Like any other injector, its purpose is to ensure appropriate flow...
fuel and dinitrogen tetroxide (N 2O 4) oxidizer. This engine used a pintleinjector, which paved the way for other engines to use similar designs. The...
2023. The pintleinjector was reduced to practice and developed by TRW starting in 1960; however, it was not until 1972 that the pintleinjector design patent...
mounted so as to minimise thermal contact with the mass of the head. A pintleinjector with a narrow spray pattern is used. At its top dead centre (TDC) the...
landing pad using one of its nine Merlin engines. The injector at the heart of Merlin is of the pintle type that was first used in the Apollo Lunar Module...
Raptor 2 uses coaxial swirl injectors to admit propellants to the combustion chamber, rather than Merlin's pintleinjectors. Before 2014, only two FFSC...
structure, pressure-fed engines using N2O4 / UDMH, later LOX /RP-1, with pintleinjectors scaled up from TRW's Lunar Module Descent Engine (LMDE). The Sea Dragon...
orbit (LEO). Space Vector fabricated a Vapak pressure fed coaxial pintleinjector engine and the Storage and Launch Carrier (SLC) system used to deploy...
valve cover via bushings that isolate the loud ticking noise that injectorpintles make. GM claims that the 1.0-liter turbo is 25 percent (3 dBA) quieter...
Inconel prechamber in the cylinder heads using Bosch pintle and seat mechanical fuel injectors. This is called indirect injection. GM used fully mechanical...
oxygen under development by Galactic Energy. The engine features a pintle type injector, a double suction coaxial split turbine pump, and a gas generator...
filter for passenger cars. 2002: Piezoelectric injector technology by Siemens. 2003: Piezoelectric injector technology by Bosch, and Delphi. 2004: BMW introduces...
stage main engine; it was used in 2006–2009. It was built around the same pintle architecture as SpaceX's Merlin engine but does not have a turbo-pump, and...
ratio was controlled by a stepper motor that operated a rack which moved a pintle that opened and closed the float bowl vent. When closed, no air could enter...
nozzles are radial out-flow nozzles with the flow deflected by a center pintle. Controlled flow-separation nozzles include: expanding nozzle, bell nozzles...
(also used on the SpaceX Merlin and Rocketdyne F-1). It utilizes a pintle-type injector. In 2021, The Verge reported that Astra Space had purchased up to...
socket-and-jaw or block and tackle (which differed from the later European pintle and gudgeon design of the 12th century). As written by a 3rd-century author...
left of the main gun, and a 7.62 mm L37A2 (GPMG) machine gun mounted on a pintle on the loader's hatch ring. 4,200 rounds of 7.62 mm ammunition are carried...
bumpers, a brush guard, a NATO slave receptacle/NATO trailer receptacle, a pintle hook, tow shackles and a 24/12-volt electrical system. The dashboard has...
ball-mounted M1919 A4 in the front hull operated by the assistant driver and a pintle mounted .50 caliber M2 Browning HB machine gun with 300 rounds on the turret...